1. Field of the Invention
The present invention relates to a picture display device for displaying images through reflection of specific wavelengths of visible light by a periodic structure produced by colloidal particles.
2. Description of the Related Art
Picture display devices of this kind known is disclosed, for example, in JP 2007-11112 A. In the device, the pixels are composed of colloidal crystals filled with polymer gel; absorption and release of a solvent by the polymer gel is brought about through application of electrical voltage to the pixels thereby inducing the colloidal crystals to undergo changes in volume through expansion and contraction. This causes the spacing between the colloidal crystals to change, producing the desired display through reflection of visible light, the wavelength of which reflected light is determined by Bragg's law. However, a drawback of the picture display device is that the colloidal crystals cannot maintain their deformed state unless voltage continues to be applied, so power consumption is considerable.
Another problem is that since the picture display device cannot display black, the content which it is possible to display is limited.